The present invention relates to a method of selecting devices for use in a fluid pipeline network, e.g. a pneumatic pipeline network or a coolant pipeline network, for supplying compressed air, cooling water, etc. to various machining devices or the like.
To select pipes, pipe joints and valves (stop valves) for use in a fluid pipeline network, first, a block diagram of the fluid pipeline network is made. In the block diagram, user-specified data items, such as the length of each section, the pressure and flow rate at a fluid source, and the flow rate at each of inlet and outlet portions, are entered. The designer temporarily selects sizes of pipes, pipe joints and valves by intuition. Then, the designer forms equations representing the flow rate at each branch point (junction point) in the fluid pipeline network and also forms equations representing the pressure and flow rate in each section. These equations are solved as simultaneous equations to obtain a pressure drop and flow rate in each section of the fluid pipeline network, and differences between the user""s desired values and the calculated values are obtained. In view of the differences, the sizes of the devices are changed, and a calculation similar to the above is performed. The calculation and the change in size of the devices are repeated to select devices that meet the user""s demand. The above-described selection method is described in xe2x80x9cThe Energy Conservationxe2x80x9d Vol. 50, No. 3, pp. 81-84, published in March, 1998, by The Energy Conservation Center Japan.
According to the conventional technique, a block diagram of a fluid pipeline network is drawn on a sheet of paper, and input conditions are entered in the block diagram. Devices to be used are temporarily selected, and a pressure drop and flow rate in the fluid pipeline network are calculated by an appropriate method. The temporary selection of devices and the calculation are repeated many times until the calculated pressure drop and flow rate reach the desired values. Therefore, much labor is required to select optimum devices.
The present invention is applied to a method of selecting devices for use in a fluid pipeline network, wherein a circuit configuration of the fluid pipeline network is made by connecting together sections between a fluid source, inlet portions, branch points and outlet portions with section devices, and a pressure at the fluid source and a flow rate at each outlet portion are given. Then, the pressure loss in each section between the fluid source and an inlet or outlet portion is adjusted to the desired value of allowable pressure loss. According to the present invention, items of data concerning devices (pipes, pipe joints and valves) are stored in databases for the various devices, and calculating equations for use in computation are also stored. Section devices are selected from the databases for the various devices, and pressures at branch points and outlet portions are computed with respect to the fluid pipeline network for which the section devices have been selected, by using the stored calculating equations.
A first object of the present invention is to provide a method of selecting devices for use in a fluid pipeline network, wherein items of data concerning devices and calculating equations for use in computation are stored in advance, and devices are temporarily selected by using the stored device data, and then computation is performed by using the stored calculating equations, thereby allowing device selection to be made easily. A second object of the present invention is to provide a method of selecting devices for use in a fluid pipeline network, wherein node positions and branch positions are displayed on a screen, and inlet portions and outlet portions are selected from the node positions, and further pipeline sections are selected from the branch positions and the node positions, thereby allowing a block diagram of the fluid pipeline network to be made easily.
The present invention is applied to a method of selecting devices for use in a fluid pipeline network, wherein a circuit configuration of the fluid pipeline network is made by connecting together sections between a fluid source, inlet portions, branch points (including junction points) and outlet portions with section devices, and a pressure at the fluid source and a flow rate at each outlet portion are given, and then the pressure loss in each section between the fluid source and an inlet or outlet portion is adjusted to the desired value of allowable pressure loss. According to a first arrangement of the present invention, items of data concerning pipes, pipe joints and valves are stored in a pipe database, a pipe joint database and a valve database, respectively, and calculating equations for use in computation are also stored. Section devices, i.e. pipes, pipe joints and valves, are selected from the pipe database, the pipe joint database and the valve database, respectively, and pressures at the branch points and the outlet portions are computed with respect to the fluid pipeline network for which the section devices have been selected, by using the stored calculating equations.
According to a second arrangement of the present invention, after the entry of the value of allowable pressure loss, the pressure at the fluid source and the flow rate at each of the inlet and outlet portions in the first arrangement, all sections of the fluid pipeline network are subjected to computation using a node analysis method to judge whether or not there is a section that does not satisfy the condition of allowable pressure loss. If there is such a section, an inlet/outlet flow rate change or a section device change is made with respect to the section. Then, a judgment as to whether or not there is a section that does not satisfy the condition of allowable pressure loss is made again by computation using the node analysis method. The inlet/outlet flow rate change or the section device change and the computation are repeated until there is no section that does not satisfy the condition of allowable pressure loss.
According to a third arrangement of the present invention, in the first or second arrangement, node positions and branch positions, which are arranged in a grid pattern, are displayed on a screen, and inlet portions, branch points and outlet portions are selected from the node positions. Further, sections to which section devices are to be connected are selected from the branch positions and the node positions to make a circuit configuration.
According to a fourth arrangement of the present invention, in the second arrangement, node positions and branch positions, which are arranged in a grid pattern, are displayed on a screen, and inlet portions, branch points and outlet portions are selected from the node positions. Further, sections to which section devices are to be connected are selected from the branch positions and the node positions to make a circuit configuration. As a result of the computation using the node analysis method, a pressure is displayed at each branch point, and a pressure and a flow rate are displayed at each of the inlet and outlet portions.
In addition, the present invention is applied to a method of selecting devices for use in a fluid pipeline network, wherein a circuit configuration of the fluid pipeline network is made by connecting together sections between inlet portions, branch points and outlet portions with section devices, and a pressure and a flow rate at each outlet portion are given, and then the pressure loss in each section between an inlet portion and an outlet portion is adjusted to the desired value of allowable pressure loss. According to a fifth arrangement of the present invention, items of data concerning pipes, pipe joints and valves are stored in a pipe database, a pipe joint database and a valve database, respectively, and calculating equations for use in computation are also stored. Section devices, i.e. pipes, pipe joints and valves, are selected from the pipe database, the pipe joint database and the valve database, respectively, and pressures at the branch points and the outlet portions are computed with respect to the fluid pipeline network for which the section devices have been selected, by using the stored calculating equations.
According to a sixth arrangement of the present invention, after the entry of the value of allowable pressure loss, the pressure at each inlet portion and the flow rate at each of the inlet and outlet portions in the fifth arrangement, all sections of the fluid pipeline network are subjected to computation using a node analysis method to judge whether or not there is a section that does not satisfy the condition of allowable pressure loss. If there is such a section, an inlet/outlet flow rate change or a section device change is made with respect to the section. Then, a judgment as to whether or not there is a section that does not satisfy the condition of allowable pressure loss is made again by computation using the node analysis method. The inlet/outlet flow rate change or the section device change and the computation are repeated until there is no section that does not satisfy the condition of allowable pressure loss.
According to a seventh arrangement of the present invention, in the fifth or sixth arrangement, node positions and branch positions, which are arranged in a grid pattern, are displayed on a screen, and inlet portions, branch points and outlet portions are selected from the node positions. Further, sections to which section devices are to be connected are selected from the branch positions and the node positions to make a circuit configuration.
According to an eighth arrangement of the present invention, in the sixth arrangement, node positions and branch positions, which are arranged in a grid pattern, are displayed on a screen, and inlet portions, branch points and outlet portions are selected from the node positions. Further, sections to which section devices are to be connected are selected from the branch positions and the node positions to make a circuit configuration. As a result of the computation using the node analysis method, a pressure is displayed at each branch point, and a pressure and a flow rate are displayed at each of the inlet and outlet portions.
In the method according to the first arrangement of the present invention, items of data concerning devices are stored in the pipe database, the pipe joint database and the valve database, and calculating equations for use in computation are also stored. Devices are temporarily selected by using the stored device data, and then computation is performed by using the stored calculating equations. Therefore, device selection can be made easily.
In the method according to the second arrangement of the present invention, the inlet/outlet flow rate change or the section device change and the computation using the node analysis method are repeated until there is no section that does not satisfy the condition of allowable pressure loss. Therefore, selection of devices desired by the user can be made accurately.
In the method according to the third arrangement of the present invention, node positions and branch positions are displayed on a screen. Inlet portions and outlet portions are selected from the node positions, and pipeline sections are selected from the branch positions and the node positions. Therefore, a block diagram of the fluid pipeline network can be made easily.
In the method according to the fourth arrangement of the present invention, as a result of the computation, a pressure is displayed at each branch point on the screen, and a pressure and a flow rate are displayed at each of the inlet and outlet portions. Therefore, the computational results can be grasped easily.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.
The invention accordingly comprises the features of construction, combinations of elements, and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.